GT500 mods

[SCJ]

SO this is my first thread post.
So hello everyone.
I am curious how many Gt500 owners are out there of this forum.
I am more of an old mustang sort of guy but obviously drive a GT500 every day 80 miles to work. I traded in an 06 mustang GT that was saleen supercharged to get the shelby.
My 07 shelby has a few basic mods already... K&N cold air, Borla ehaust.
So I have a few ?'s for some of the Shelby owners out there.

1 Is the stock tune bad enough to warrant a tune and what kind of hidden HP can be found just with a good tune?

2 Headers or not? do they actually make much of a difference?

3 Anyone change to the smaller supercharger pulley and then retuned it? What was the before/after HP #s

4 Can you during a retune... change when the boost comes on, earlier?

5 What kind of HP have you been getting with the stock supercharger before it needs to be upgraded to a bigger one?


I need the car to stay drivable but would like a bit more and looking at the best ideas.
Thanks,
Rich

 

[Tommy]

I'm sure Emilio (WickedStangs) will chime in here.

Mine isn't quite stock anymore :rofl: , but I wouldn't be able to tell you which way to go. I just have lots of nice mods on it and plan on "collecting" it.

 

[boostedmach]

My father has a GT500, with a pulley intake and tune, you are looking at 520+rwhp and a top speed of 200mph+

The boost is in proportion to rpm and you cant dial in the boost.
Stock blowers are making 550+rwhp.

I can see if my dad will chime in and give any other advise.

-boosted

 

[SCJ]

I know that you can't get more PSI boost with tuning, I am much smarter car wise than that. What I meant was...can the computer be tuned to add the boost sooner. It can be at 3500rpm but doesn't whine until the pedal is mashed.
I know that if I mash the pedal it will add all the boost that it can make for it's given RPM,
But.. is it possible to tune it so that it adds all the boost that it has available for the given RPM at only half throttle.
So in Theory at partial throttle it may make a little more cruising power, or a little more low end, maybe even getting a little better MPG
It's not a big deal or a big thought because if I want to drive it hard the pedal will be mashed anyway.
I put $45 of gas in it every 3 days, ouch

 

[blackstallion06]

Wow that is some car list you have is that what you have in the garage? Have me drooling. Those are some very rare cars. I had a 66 Falcon and is process of buying a 65

 

[beejay31000]

a supercharger is run off of engine speed. no you cannot electronically "add" boost sooner, what you can do is change the pully size, which makes the supercharger spin faster relitive to the engine speed. creating boost sooner, and eventually higher peak boost in the upper RPM.

 

[beejay31000]

what your thinking of is a turbo, where you can electronically control the wastegate and bleed off boost until you want it to come in.....that does not exist in a engine driven eaton blower

 

[SCJ]

BeeJay31000
I was talking to another Gt500 owner the other day and they said that they had their car tuned to bring the boost in sooner. I didn't think it was possible and it didn't make sense. You are right I was thinking more of a wastegate situation. I haven't had mine tuned yet so I wasn't sure and ask that as one of my ?'s. It was a stupid ? to ask in the first place. I just went with what they said and didn't think it through myself.
I still would like the other ?'s that I ask to be answered, I think they are more legit.
I also wondered if changing the pulley would give much more of a seat of the pants feel. Maybe the car will just smoke the tires in third instead of second, and make it even harder to hook and thereby make it even slower on the street tires.
Just would like to hear from some of you to see if the mods are worth doing or not.

Blackstallion06,
Yes all of the cars are in the garage. I love my garage, it's much bigger than my house. Most of them are very rare. The 70 and 71 are 1 of 1's only ones like them. My 70 SCJ has a 1:18 scale model made of it, and funny thing about that is I owned the model before the real car.
My 70 Mach is the only SCJ, Grabbergreen, 4spd, black interior, car that was ordered with spoilers and rear window louvers, like the model has.
A couple are just covered awaiting resto. One is on the rotissorie in my paint booth very close to paint. others are nice driveable condition. I just got the 69 SCJ 428 back from getting rebuilt Friday and will try to get it back in soon, but will miss the San Diego Embarcadero show with it Oct.4.

Talking about buying a 65 Falcon....I thought I might sell mine...It doesn't get much love anymore. I dropped a 351C (cleveland) into it last summer. The motor is VERY nasty (built by Total Performance). It has a 4spd, 9" posi rear, disc brakes, 3"exhaust, alum radiator, at list goes on. I did not cut the shock towers and barely squeezed the headers in. It still wears it's original paint, and has absolutely no rust or body damage. It has some spray can primer over some of the thin paint areas. I drive it every now and then to keep the carb cleaned out and get an adrenalin rush. Someday I will put a week into it and paint it Chip Foose style Black bottom/candy orange top.

I don't want you guys to get the wrong picture of me. I am not wealthy. I work hard every day (teacher), and have young kids. I have just been very lucky finding some rare cars at the right time. I have looked for the cars I love since I was a kid and have hung on to some of them.
I restore my cars all myself, taking 3-4 years sometimes to do one. I do all the body work, paint, and mechanicals. Some times on the expensive rare motors like the 428 I will pay to have them built so I don't mess the rare stuff up.
I have a hard time showing the shelby at shows because I haven't put any sweat into it yet, It's just a Shelby like everyone else's. I admire the cars that the owner has put some work into. The white Lamborghini that was at EL Cajon last week bugged me, just a big $$show. I admire the cars that you and others put some effort in to make them special.
Later:hello:

 

[wickedstangs]

My 07 shelby has a few basic mods already... K&N cold air, Borla ehaust.
So I have a few ?'s for some of the Shelby owners out there.

1 Is the stock tune bad enough to warrant a tune and what kind of hidden HP can be found just with a good tune? Yes the Stock Tune on our GT500 are bad. And if you installed a K&N you definitely want a tune.

2 Headers or not? do they actually make much of a difference? I have seen these cars with more than 700rwhp with the stock manifolds

3 Anyone change to the smaller supercharger pulley and then retuned it? What was the before/after HP #s
I just purchased a 2.6 upper pulley and an idler which they say is good for 80 more rwhp. A stock GT500 rwhp is in the range of 440-460

4 Can you during a retune... change when the boost comes on, earlier? NO
Beejay answered that one.

5 What kind of HP have you been getting with the stock supercharger before it needs to be upgraded to a bigger one? depends you can port and polish a stock supercharger for increased horsepower

I need the car to stay drivable but would like a bit more and looking at the best ideas.
Thanks,
Rich

A set of 3.73 and 2.6upper and idler with exhaust and CAI is the way to go. How much more HP do you want?

 

[SCJ]

Want as much HP as possible without messing up the drivability.

 

[beejay31000]

hmmmm....theres almost no limit....lol. built block......KB up top. 1000hp. easily drivable daily.....lol. just do the basics for starters......GEARS....pully, intake, exhaust, tune. you will like what you get.

 

[jamesb]

1 Is the stock tune bad enough to warrant a tune and what kind of hidden HP can be found just with a good tune?

Yes.

2 Headers or not? do they actually make much of a difference?

Don't know, but I hope you know a smog guy because they are illegal here.

3 Anyone change to the smaller supercharger pulley and then retuned it? What was the before/after HP #s

I didn't tune it before so I don't know the before number. Its 525rwhp with upper and lower now.

4 Can you during a retune... change when the boost comes on, earlier?

No. But the cold air intake feels like it does doesn't it?

5 What kind of HP have you been getting with the stock supercharger before it needs to be upgraded to a bigger one?

If you spend $5000 bucks you can get 600wrhp out of it, so I'm told. So stop wasting your money and get a KB mammoth. They are smog legal too

I need the car to stay drivable but would like a bit more and looking at the best ideas.

I've read that with the KB its easy to swap pulleys, and with a bigger pulley on top, its a lot more polite. I have no experience with a KB however.